/**
 * Copyright (c) 2011-2017, dafei 李飞 (myaniu AT gmail DOT com)
 *
 * Licensed under the Apache License, Version 2.0 (the "License"); you may not
 * use this file except in compliance with the License. You may obtain a copy of
 * the License at
 *
 * http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
 * WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
 * License for the specific language governing permissions and limitations under
 * the License.
 */
package top.jnaw.jee.plugin.shiro;

import java.lang.annotation.Annotation;
import java.util.Arrays;
import org.apache.shiro.authz.AuthorizationException;
import org.apache.shiro.authz.annotation.Logical;
import org.apache.shiro.authz.annotation.RequiresRoles;

/**
 * 基于角色的访问控制处理器，非单例模式运行。
 *
 * @author dafei
 */
class RoleAuthzHandler extends AbstractAuthzHandler {

  private final Annotation annotation;

  public RoleAuthzHandler(Annotation annotation) {
    this.annotation = annotation;
  }

  public void assertAuthorized() throws AuthorizationException {
    //if (!(annotation instanceof RequiresRoles)) return;
    RequiresRoles rrAnnotation = (RequiresRoles) annotation;
    String[] roles = rrAnnotation.value();

    if (roles.length == 1) {
      getSubject().checkRole(roles[0]);
      return;
    }
    if (Logical.AND.equals(rrAnnotation.logical())) {
      getSubject().checkRoles(Arrays.asList(roles));
      return;
    }
    if (Logical.OR.equals(rrAnnotation.logical())) {
      // Avoid processing exceptions unnecessarily - "delay" throwing the exception by calling hasRole first
      boolean hasAtLeastOneRole = false;
      for (String role : roles) {
        if (getSubject().hasRole(role)) {
          hasAtLeastOneRole = true;
        }
      }
      // Cause the exception if none of the role match, note that the exception message will be a bit misleading
      if (!hasAtLeastOneRole) {
        getSubject().checkRole(roles[0]);
      }
    }
  }
}
